SYNTHESIS AND CHARACTERIZATION OF NITROCHROMENE BASED DERIVATIVES

Abstract

Chromene (2-14 Chromene) contains benzopyran ring structures exhibit a large number of biological activities such as antihypertensive, gastro protective agent, antitumor activity, anticoagulant, antibacterial, vasodilator, anthelminthic activities. Pyrazole derivatives show a vast range of biological activity such as anti-inflammatory, antimicrobial, selective enzyme inhibitors such as oxidoreductase and alchohal dehydrogenase, CNS regulants. hypoglycemic activity, antihypertensive activity. Chromene itself biologically active molecule if combine chromene with pyrazole expect to increase biological activity. An efficient method developed for synthesis of nitrochromane based pyrazole derivatives. Intermediates nitro styrenes (la-lOa) synthesized by reaction of different aldehydes with nitromethane in presence of sodium hydroxide at 0 0C to room temperature obtained upto 95% yield. Nitrochromcne (lb-lOb) are synthesized from nitro styrene and salicyldehyde using DABCO as a catalyst under solvent free condition in excellent yield (80-92%). Nitrochromane based 1,3 diones (Ic-lOc) synthesized via Michael addition of 1,3 dione on nitrchromcne in presence of potassium carbonate at room temperature in good yield (70%-80%), which condensed with hydrazine hydrate to form pyrazole derivative (id-lOd) in excellent yield (84-96%).